Multipolar electromagnetic generator

ABSTRACT

A power generator comprises a first array of magnets or a first sheet magnet, a first conductor, and a power management circuit. The first array comprises a one dimensional or two dimensional array of magnets. The first sheet magnet includes a one dimensional or two dimensional array of alternating magnetic poles. The first conductor comprises a first serpentine conductor that is on a plurality of layers of a first multilayer printed circuit board or a first serpentine conductor that is on one or more planes. The power management circuit provides DC power as a result of relative motion between the first array of magnets or the first sheet magnet and the first conductor

CROSS REFERENCE TO OTHER APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 12/855,835, entitled MULTIPOLAR ELECTROMAGNETIC GENERATOR filedAug. 13, 2010 which is incorporated herein by reference for allpurposes, which claims priority to U.S. Provisional Application No.61/242,805, entitled MULTIPOLAR ELECTROMAGNETIC GENERATOR filed Sep. 16,2009 which is incorporated herein by reference for all purposes.

BACKGROUND OF THE INVENTION

There are many sensor application areas where there is a clear need forinnovative power solutions. The market for wireless sensor networks inindustrial automation, supply chain management, construction, homeautomation, asset tracking and environmental monitoring is expected togrow to well over 400 million devices by 2012. The average useful lifeof such a system is targeted to be more than 10 years, which means thatthe stand-alone usage of conventional batteries poses significantbarriers to being a robust energy solution.

Harvesting energy from motion has been the focus of intense research.There are three common technological approaches: piezoelectric,electrostatic, and electromagnetic. Numerous research groups andcompanies have tried to develop miniature thin-film piezoelectricdevices to harness vibrations in the last 20 years. However, one problemis that thin-film piezoelectric energy have limited power output becauseof their high-voltage low-current output, typically tens of volts andless than nanoamperes, which makes it difficult to convert withoutsubstantial losses. Another problem is the high intrinsic frequencies ofpiezoelectric (PZT) materials, typically around MHz, that can't becoupled to any vibrations or cyclical motion available for practicalapplications.

Other groups have focused on developing electrostatic generators.Electrostatic generators have limited power output similar topiezoelectric generators also due to the fact that they produce onlyhigh voltages and low electrical currents. Furthermore, it can be shownthat in most cases electrostatic generators have lower power densitiesthan either piezoelectric or electromagnetic generators due to therelatively low energy density of an electrostatic air gap on which theelectrostatic generators rely.

On the other hand, electromagnetic power generators have the potentialto supply relatively large amounts of power without being restricted tothe intrinsic frequencies of piezoelectric materials. However,generating sufficient power at a desired compact scale has still notbeen achieved. Further, the unmatched natural frequency of a small scaledevice, typically kHz, cannot be coupled to the vibrations that arecommonly available for most applications. Lastly, current designsrequire state-of-the-art precision machining and assembly (e.g., e lasercutting, electrical discharge machining (EDM), and CNC machining) ormicromachining and thin film technologies (e.g., Magnetic materials,both permanent magnets and magnetic alloys, are difficult and expensiveto do as thinfilms. Micromachining in general gets expensive as the sizeof the device gets larger, and in this case the devices need to berelatively large (˜1 cm̂2) to give any reasonable amount of power. Atthat size, micromachining becomes quite expensive.) that drasticallyraise manufacturing costs beyond that of batteries.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are disclosed in the followingdetailed description and the accompanying drawings.

FIG. 1A is a block diagram illustrating an embodiment of a portion of apower generator.

FIG. 1B is a block diagram illustrating an embodiment of a portion of apower generator.

FIG. 1C is a block diagram illustrating an embodiment of a portion of apower generator.

FIG. 1D is a block diagram illustrating an embodiment of a portion of apower generator.

FIG. 1E is a block diagram illustrating an embodiment of a portion of apower generator.

FIG. 1F is a block diagram illustrating an embodiment of a portion of apower generator.

FIG. 2A is a block diagram illustrating an embodiment of a powergenerator.

FIG. 2B are block diagrams illustrating embodiments of suspension sheetgeometries.

FIG. 3A is a block diagram illustrating an embodiment of a conductorlayout on a layer of a multilayer circuit board.

FIG. 3B is a block diagram illustrating an embodiment of a conductor incross section view.

FIG. 3C is a block diagram illustrating an embodiment of a conductor ona layer of a multilayer circuit board.

FIG. 3D is a block diagram illustrating an embodiment of a conductor ontwo layers of a multilayer circuit board.

FIG. 3E is a block diagram illustrating an embodiment of a multilayercircuit board with five serpentine conductors on each one of multiplelayers. FIG. 4B is a block diagram illustrating an embodiment of amultipole magnet in the form of a magnetic sheet.

FIG. 4A is a block diagram illustrating an embodiment of a multipolemagnet.

FIG. 4B is a block diagram illustrating an embodiment of a multipolemagnet in the form of a magnetic sheet.

FIG. 4C is a block diagram illustrating an embodiment of a multipolemagnet in the form of an array of bar magnets.

FIG. 5A is a block diagram illustrating an embodiment of a powergenerator.

FIG. 5B is a block diagram illustrating an embodiment of a powergenerator.

FIG. 6 are block diagrams illustrating embodiments of a coil conductor.

FIG. 7 is a block diagram illustrating an embodiment of a powermanagement circuit.

FIG. 8 is a flow diagram illustrating an embodiment of a process forgenerating power.

FIG. 9 is a flow diagram illustrating an embodiment of a process forpower management.

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term ‘processor’refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

A power generator is disclosed. In some embodiments, the power generatorcomprises an array of magnets positioned on a planar surface, aconductor, and a power management circuit. The array comprises a onedimensional or two dimensional array of magnets. The conductor comprisesa serpentine conductor that is on a plurality of layers of a multilayerprinted circuit board. The power management circuit generates DC poweras a result of relative motion between the array of magnets and theconductor.

A power generator is disclosed. In some embodiments, the power generatorcomprises a sheet magnet, a conductor, and a power management circuit.The sheet magnet includes a one dimensional or two dimensional array ofalternating magnetic poles. The conductor comprises a serpentineconductor that is on more than a single plane. The power managementcircuit generates DC power as a result of relative motion between thesheet magnet and the conductor.

A power generator is disclosed. In some embodiment, the power generatorcomprises a mutlipole magnet, a set of coils, and a power managementcircuit. The multipole magnet and the coils oscillate relative to eachother. A voltage and/or current is/are generated by the relative motionbetween the multipole magnet and set of coils. A power managementcircuit conditions the power generated for use by standard electronicsor electrical systems.

In some embodiments, the conductor or set of coils is implemented as amultilayer circuit board. If the circuit board is fixed, or stationary,the magnet is attached to a flexure that allows it to oscillate withrespect to the conductor. If the magnet is fixed, the circuit board (orother embodiment of the coils or conductor(s)) is securely attached to aflexure that allows it to oscillate with respect to the magnet.

In some embodiments, a multilayer circuit board has a conductor on thesurfaces of the multiple layers of a multilayer circuit board thatpresent an area to the magnetic field of a multipole magnet. Themultilayer circuit board is moved (e.g., oscillated) relative to themultipole magnet, or alternatively the magnet is moved relative to thecircuit board. The conductor of the multilayer circuit board experiencesa change in magnetic flux enclosed by the conductor due to the relativemotion between the multilayer circuit board and the multipole magnetleading to a voltage and/or current generated across the planar coilcreated by the conductor. In some embodiments, a power managementcircuit conditions the power by converting an alternating voltage (e.g.,due to the oscillation) to DC voltage by using rectification (e.g., adiode circuit) and storing the energy on a capacitor and/or a battery orproviding the power directly to an electrical load or circuit that usesthe power.

FIG. 1A is a block diagram illustrating an embodiment of a portion of apower generator. In the example shown, multipole magnet 100 andmultipole magnet 102 each comprise a series of magnets with a cycle ofadjacent north-south and then south-north oriented magnets. In someembodiments, multipole magnet 100 and/or multipole magnet 102comprise(s) a sheet magnet (e.g., NdFeB sheet magnet). In someembodiments, a sheet magnet has a surface magnetic field of ˜150 mTesla.In various embodiments, the pitch for the magnet is a couple ofmillimeters, 1 millimeter, a fraction of a millimeter, or any otherappropriate pitch. In some embodiments, the pitch is matched to therange of motion being harvested for energy. In some embodiments, thereis only one multipole magnet (e.g., multipole magnet 100 or multipolemagnet 102) presenting a field to multilayer circuit board.

Multipole magnet 100 and multipole magnet 102 each presents a magneticfield to multilayer circuit board 104. Multipole magnet 100 andmultipole magnet 102 are on opposite sides of multilayer circuit board104. Multipole magnet 100 and multipole magnet 102 are aligned such thatthe stripes of north of one magnet line up with the stripes of south ofthe other magnet. Mutlilayer circuit board 104 experiences a highermagnetic field because of the two magnets (multipole magnet 100 andmultipole magnet 102). Multilayer circuit board 104 moves relative tomultipole magnet 100 and multipole magnet 102. Multilayer circuit board104 is oscillated using suspension 106 and suspension 110. Suspension106 suspends multilayer circuit board 104 from fixed structure 108.Suspension 110 suspends multilayer circuit board 104 from fixedstructure 112. Suspension 106 and suspension 110 are selected such thatthe oscillation frequency of the suspended multilayer circuit board 104is tailored for the motion experienced by the power generator. Invarious embodiments, the tailoring is achieved by selecting the size,material, mass (e.g., adding mass), or any other appropriatecharacteristic of multilayer circuit board 104 and/or suspension 106and/or suspension 110. In some embodiments, weight is added tomultilayer circuit board 104. In some embodiments, suspension 106 and/orsuspension 110 are made using low cost stamping and cutting. In someembodiments, suspension 106 and/or suspension 110 are made of plastic.In some embodiments, suspension 106 and/or suspension 110 is/are part ofa suspension sheet, where the suspension sheet is coupled to multilayercircuit board 104.

In some embodiments, multilayer circuit board 104 is approximately 5.5cm wide, 5.5 cm tall, and 1 mm thick. Multilayer circuit board 104weighs 10 g and is suspended by using a stamped metal suspension 106 andsuspension 110 with a resonant frequency of approximately 160 Hz.

In some embodiments, multilayer circuit board 104 is approximately 3.5cm wide, 4 cm tall, and 1 mm thick. Multilayer circuit board 104 weighs4 g and is suspended by using a metal suspension 106 and metalsuspension 110 with a resonant frequency of approximately 80 Hz.

FIG. 1B is a block diagram illustrating an embodiment of a portion of apower generator. In the example shown, multipole magnet 120 andmultipole magnet 122 each comprise a series of magnets with a cycle ofadjacent north-south and then south-north oriented magnets. In someembodiments, multipole magnet 120 and/or multipole magnet 122comprise(s) a sheet magnet (e.g., NdFeB rubber sheet magnet). In someembodiments, a sheet magnet has a surface magnetic field of ˜150 mTesla.In various embodiments, the pitch for the magnet is a couple ofmillimeters, 1 millimeter, a fraction of a millimeter, or any otherappropriate pitch. In some embodiments, the pitch is matched to therange of motion being harvested for energy. In some embodiments, thereis only one multipole magnet (e.g., multipole magnet 120 or multipolemagnet 122) presenting a field to multilayer circuit board.

Multipole magnet 120 and multipole magnet 122 each presents a magneticfield to multilayer circuit board 124. Multipole magnet 120 andmultipole magnet 122 are on opposite sides of multilayer circuit board124. Multipole magnet 120 and multipole magnet 122 are aligned such thatthe stripes of north of one magnet line up with the stripes of south ofthe other magnet. Mutlilayer circuit board 104 experiences a highermagnetic field because of the two magnets (multipole magnet 120 andmultipole magnet 122). Multilayer circuit board 124 moves relative tomultipole magnet 120 and multipole magnet 122. Multipole magnet 120 isoscillated using suspension 125 and suspension 129. Suspension 125suspends multipole magnet 120 from fixed structure 127. Suspension 129suspends multipole magnet 120 from fixed structure 132. Suspension 126suspends multipole magnet 122 from fixed structure 128. Suspension 130suspends multipole magnet 122 from fixed structure 131. Suspension 125,suspension 126, suspension 129, and suspension 130 are selected suchthat the oscillation frequency of the suspended multipole magnet 120 andmultipole magnet 122 is/are tailored for the motion experienced by thepower generator. In various embodiments, the tailoring is achieved byselecting the size, material, mass (e.g., adding mass), or any otherappropriate characteristic of multipole magnet 120 and/or multipolemagnet 122 and/or suspension 125, suspension 126, suspension 129, and/orsuspension 130. In some embodiments, weight is added to multilayercircuit board 124. In some embodiments, suspension 125, suspension 126,suspension 129, and/or suspension 130 are made using low cost stampingand cutting. In some embodiments, suspension 125, suspension 126,suspension 129, and/or suspension 130 are made of plastic. In someembodiments, suspension 125, suspension 126, suspension 129, and/orsuspension 130. is/are part of a suspension sheet, where the suspensionsheet is coupled to multipole magnet 120 or multipole magnet 122.Mutlipole magnet 120 and multipole magnet 122 are each allowed tooscillate independently.

FIG. 1C is a block diagram illustrating an embodiment of a portion of apower generator. In the example shown, multipole magnet 140 andmultipole magnet 142 each comprise a series of magnets with a cycle ofadjacent north-south and then south-north oriented magnets. In someembodiments, multipole magnet 140 and/or multipole magnet 142comprise(s) a sheet magnet (e.g., NdFeB sheet magnet). In someembodiments, a sheet magnet has a surface magnetic field of ˜150 mTesla.In various embodiments, the pitch for the magnet is a couple ofmillimeters, 1 millimeter, a fraction of a millimeter, or any otherappropriate pitch. In some embodiments, the pitch is matched to therange of motion being harvested for energy. In some embodiments, thereis only one multipole magnet (e.g., multipole magnet 140 or multipolemagnet 142) presenting a field to multilayer circuit board.

Multipole magnet 140 and multipole magnet 142 each presents a magneticfield to multilayer circuit board 144. Multipole magnet 140 andmultipole magnet 142 are on opposite sides of multilayer circuit board144. Multipole magnet 140 and multipole magnet 142 are aligned in theresting position of the suspensions such that the stripes of north ofone magnet line up with the stripes of south of the other magnet.Mutlilayer circuit board 144 experiences a higher magnetic field becauseof the two magnets (multipole magnet 140 and multipole magnet 142).Multilayer circuit board 144 moves relative to multipole magnet 140 andmultipole magnet 142. Multipole magnet 140 and multipole magnet 142 areoscillated using suspension 146 and suspension 150. Suspension 146suspends multipole magnet 140 and mutlipole magnet 142 from fixedstructure 148. Suspension 150 suspends multipole magnet 140 andmultipole magnet 142 from fixed structure 152. Suspension 146 andsuspension 150 are selected such that the oscillation frequency of thesuspended multipole magnet 140 and multipole magnet 142 is/are tailoredfor the motion experienced by the power generator. In variousembodiments, the tailoring is achieved by selecting the size, material,mass (e.g., adding mass), or any other appropriate characteristic ofmultipole magnet 140 and/or multipole magnet 142 and/or suspension 146and/or suspension 150. In some embodiments, weight is added tomultilayer circuit board 144. In some embodiments, suspension 146 and/orsuspension 150 are made using low cost stamping and cutting. In someembodiments, suspension 146 and/or suspension 150 are made of plastic.In some embodiments, or suspension 146 and/or suspension 150 is/are partof a suspension sheet, where the suspension sheet is coupled tomultipole magnet 140 or multipole magnet 142. Mutlipole magnet 140 andmultipole magnet 142 are coupled so that they oscillate together.

FIG. 1D is a block diagram illustrating an embodiment of a portion of apower generator. In the example shown, multipole magnet 160 comprises aseries of magnets with a cycle of adjacent north-south and thensouth-north oriented magnets. In some embodiments, multipole magnet 160comprises a sheet magnet (e.g., NdFeB sheet magnet). In someembodiments, a sheet magnet has a surface magnetic field of ˜150 mTesla.In various embodiments, the pitch for the magnet is a couple ofmillimeters, 1 millimeter, a fraction of a millimeter, or any otherappropriate pitch. In some embodiments, the pitch is matched to therange of motion being harvested for energy.

Multipole magnet 160 present a magnetic field to multilayer circuitboard 164 and multilayer circuit board 165. Multilayer circuit board 164and multilayer circuit board 165 are on opposite sides of mutlipolemagnet 160. Multilayer circuit board 164 and multilayer circuit board165 are aligned such that the stripes of north of one magnet line upwith the conductor lines in the circuit boards in the resting positionof the suspensions. The motion of multipole magnet 160 presents a changein magnetic flux enclosed by the areas between conductors on multilayercircuit board 164 and multilayer circuit board 165 such that a currentis generated. Multipole magnet 160 is oscillated using suspension 166and suspension 170. Suspension 166 suspends multipole magnet 160 fromfixed structure 168. Suspension 170 suspends multipole magnet 160 fromfixed structure 172. Suspension 166 and suspension 170 are selected suchthat the oscillation frequency of the suspended multipole magnet 160 istailored for the motion experienced by the power generator. In variousembodiments, the tailoring is achieved by selecting the size, material,mass (e.g., adding mass), or any other appropriate characteristic ofmultipole magnet 160 and/or suspension 166 and/or suspension 170. Insome embodiments, weight is added to mutlipole magnet 160. In someembodiments, suspension 166 and/or suspension 170 are made using lowcost stamping and cutting. In some embodiments, suspension 166 and/orsuspension 170 are made of plastic. In some embodiments, or suspension166 and/or suspension 170 is/are part of a suspension sheet, where thesuspension sheet is coupled to multipole magnet 160.

In some embodiments, multipole magnet 160 is approximately 3.5 cm wide,4 cm tall, and 1 mm thick and weighs about 4 g. Multipole magnet 160 issuspended by using a stamped metal suspension 166 and suspension 170with a resonant frequency of approximately 80 Hz.

FIG. 1E is a block diagram illustrating an embodiment of a portion of apower generator. In the example shown, multipole magnet 174 comprises aseries of magnets with a cycle of adjacent north-south and thensouth-north oriented magnets. In some embodiments, multipole magnet 174comprises a sheet magnet (e.g., NdFeB sheet magnet). In someembodiments, a sheet magnet has a surface magnetic field of ˜150 mTesla.In various embodiments, the pitch for the magnet is a couple ofmillimeters, 1 millimeter, a fraction of a millimeter, or any otherappropriate pitch. In some embodiments, the pitch is matched to therange of motion being harvested for energy.

Multipole magnet 174 present a magnetic field to multilayer circuitboard 184. Multilayer circuit board 184 is aligned such that the stripesof north of one magnet line up with the conductor lines in multilayercircuit board 184 in the resting position of the suspensions. The motionof multipole magnet 174 presents a change in magnetic flux enclosed bythe areas between conductors on multilayer circuit board 184 such that avoltage and/or current is generated. Multipole magnet 174 is oscillatedusing suspension 176 and suspension 180. Suspension 176 suspendsmultipole magnet 174 from fixed structure 178. Suspension 180 suspendsmultipole magnet 174 from fixed structure 182. Suspension 176 andsuspension 180 are selected such that the oscillation frequency of thesuspended multipole magnet 174 is tailored for the motion experienced bythe power generator. In various embodiments, the tailoring is achievedby selecting the size, material, mass (e.g., adding mass), or any otherappropriate characteristic of multipole magnet 174 and/or suspension 176and/or suspension 180. In some embodiments, weight is added to mutlipolemagnet 174. In some embodiments, suspension 176 and/or suspension 180are made using low cost stamping and cutting. In some embodiments,suspension 176 and/or suspension 180 are made of plastic. In someembodiments, or suspension 176 and/or suspension 180 is/are part of asuspension sheet, where the suspension sheet is coupled to multipolemagnet 174.

In some embodiments, multipole magnet 174 is approximately 3.5 cm wide,4 cm tall, and 1 mm thick. Multipole magnet 174 weighs 4 g and issuspended by using a stamped metal suspension 176 and suspension 180with a resonant frequency of approximately 80 Hz.

FIG. 1F is a block diagram illustrating an embodiment of a portion of apower generator. In the example shown, multipole magnet 196 comprises aseries of magnets with a cycle of adjacent north-south and thensouth-north oriented magnets. In some embodiments, multipole magnet 196comprises a sheet magnet (e.g., NdFeB sheet magnet). In someembodiments, a sheet magnet has a surface magnetic field of ˜150 mTesla.In various embodiments, the pitch for the magnet is a couple ofmillimeters, 1 millimeter, a fraction of a millimeter, or any otherappropriate pitch. In some embodiments, the pitch is matched to therange of motion being harvested for energy.

Multipole magnet 196 present a magnetic field to multilayer circuitboard 186. Multilayer circuit board 186 is aligned such that the stripesof north of one magnet line up with the conductor lines in multilayercircuit board 186 in the resting position of the suspensions. The motionof multilayer circuit board 186 presents a change in magnetic fluxenclosed by the areas between conductors on multipole magnet 196 suchthat a voltage and/or current is generated. Multilayer circuit board 186is oscillated using suspension 192 and suspension 188. Suspension 188suspends multilayer circuit board 186 from fixed structure 190.Suspension 192 suspends multilayer circuit board 186 from fixedstructure 194. Suspension 192 and suspension 188 are selected such thatthe oscillation frequency of the suspended multilayer circuit board 186is tailored for the motion experienced by the power generator. Invarious embodiments, the tailoring is achieved by selecting the size,material, mass (e.g., adding mass), or any other appropriatecharacteristic of multilayer circuit board 186 and/or suspension 192and/or suspension 188. In some embodiments, weight is added tomultilayer circuit board 186. In some embodiments, suspension 192 and/orsuspension 188 are made using low cost stamping and cutting. In someembodiments, suspension 192 and/or suspension 188 are made of plastic.In some embodiments, or suspension 192 and/or suspension 188 is/are partof a suspension sheet, where the suspension sheet is coupled tomultilayer circuit board 186.

FIG. 2A is a block diagram illustrating an embodiment of a powergenerator. In the example shown, suspension sheet 200 is coupled tomultipole magnet 202. Suspension sheet 200 is coupled to a surroundingstructure—for example, by flexures 208—making a spring-mass structurethat is capable of motion/oscillation in the direction indicated by 210.Multipole magnet 202 comprises a sheet magnet with alternating stripesof poles. The direction of motion along 210 is perpendicular to thestripes of multipole magnet 202 so that the motion causes a change inmagnetic field to be experienced for a fixed structure nearby the movingsheet. Suspension sheet 200 and multipole magnet 202 move relative tomultilayer circuit board 206. Multilayer circuit board 206 includesconductor 204 arranged to generate current in the event that a change inmagnetic flux from a multipole magnet moves (e.g., multipole magnet202). Conductor 204 is arranged in a serpentine pattern with long linesparallel to the magnetic sheet pole stripes and short legs across thestripes. In some embodiments, a conductor appears on a plurality oflayers of multilayer circuit board 206. In various embodiments,conductors on each of the plurality of layers are electrically separatefrom each other, conductors on each of the plurality of layers areelectrically connected, conductors on each of the plurality of layersare “in parallel” with each layer conductor path—for example, similarcircuit path on each layer connected at the same ends on each layer,conductors on each of the plurality of layers are “in series” for eachlayer conductor path—for example, similar circuit path on each layerconnected at opposite ends on each layer, or any other appropriateconductor connectivity and layout.

In some embodiments, multipole magnet 202 has dimensions 35 mm×40 mm×2mm. There are 20 stripes of width 2 mm each. The strength of the magnetis about 0.3 Tesla in the range of interest (i.e., where multilayercircuit board 206 oscillates). The serpentines are arranged to line upwith the magnetic pole stripes, and there are 20×3=60 on each layer ofthe printed circuit board (see FIG. 3A). In various embodiments, thereare 3 loops, 5 loops, or any other appropriate number of loops. Thereare 6 layers in multilayer circuit board 206 for a total of 360conductors. The total mass of the oscillator is 6 grams, which includesthe circuit board and some connectors and spring attachments. Theresulting oscillation frequency is about 75 Hz. The peak open circuitvoltage generated is about 5 volts. The coil resistance is about 10Ohms, so when the coil is terminated with 10 Ohm resistor, the resultingpeak power is 2.5 watts (5 volts, 0.5 amps). However, the average powergenerated over 20 mSec, which is the relevant time window for a lightswitch, is about 100 mW. Since this product operates in free oscillationmode, there really isn't an off-resonance operating point.

FIG. 2B are block diagrams illustrating embodiments of suspension sheetgeometries. In the examples shown, attachment points are shown for eachsuspension sheet (e.g., 220, 230, 240, 250, 260, 270, 280, and 290) anda direction for oscillation (e.g., 222, 232, 242, 252, 262, 272, 282,and 292). In some embodiments, the suspension sheets in FIG. 2B are madeof a material that is cut or stamped or molded. In some embodiments, thesuspension sheets are fabricated from a plastic. In various embodiments,the spring constant of the suspension is tuned by selecting materialtype, selecting material thickness, selecting material width along thearms that extend from the central body of the suspension platform to theattachment points, or any other appropriate manner of tuning the springconstant. In various embodiments, the oscillation frequency of thesuspension plus multipole magnet or multilayer circuit board is tuned byselecting material type of the suspension, selecting mass of the centralbody of the suspension, selecting mass of the multipole magnet,selecting mass of the multilayer circuit board, or any other appropriatemanner of tuning the oscillation frequency.

FIG. 3A is a block diagram illustrating an embodiment of a conductorlayout on a layer of a multilayer circuit board. In the example shown,conductor end 300 is coupled to conductor 302 running parallel to amagnet stripe on a multipole magnet. Conductor 302 is coupled toconductor 306 running across the magnet stripe. Conductor 306 is alsocoupled to conductor 308 running parallel to the magnet stripe in themultipole magnet. Similar conductors are arranged to surround othermagnet stripes of the multipole magnet and are configured to generate acurrent when the multipole magnet moves from the change in magnetic fluxenclosed by the area between conductors (e.g., between 308 and conductor310). The conductor is arranged in a serpentine which doubles back andends at conductor end 304. In this way, there are multiple serpentineconductors wired in series on a single layer of the circuit board. FIG.3A shows two serpentine conductors in series. In some embodiments,conductor is on multiple layers of a circuit board and connected toother layers using vias.

FIG. 3B is a block diagram illustrating an embodiment of a conductor incross section view. In the example shown, multilayer circuit board 320includes a plurality of conductors shown in cross section (e.g.,conductor 322). The conductors are similar in pattern to those shown inFIG. 3A on each layer of the multilayer circuit board.

FIG. 3C is a block diagram illustrating an embodiment of a conductor ona layer of a multilayer circuit board. In the example shown, the loopcreated by conductor 340, conductor 342, and conductor 344 generatescurrent from one polarity of magnet of the magnetic sheet. The loopcreated by conductor 346, conductor 348, and conductor 350 generatescurrent from another polarity of magnet of the magnetic sheet. The loopsare connected in series through vias (e.g., vias 352). Conductor 354 ison a different layer than conductor 340, conductor 342, conductor 344,conductor 346, conductor 348, and conductor 350. In the example shown,conductor end 340 is connected to conductor end 344 through a series ofvias (e.g., via 348). In the example shown, all conductors are on thesame layer except those shown with a dotted line (e.g. 354). The end ofconductor 344 attaches to a via which drops to a different layer so thatit can go back underneath 340, but conductors 340 and 344 are on thesame layer. Loop 390 generates a current from one polarity of magnet ofthe magnetic sheet. Loop 392 generates a current from another polarityof magnet of the magnetic sheet.

FIG. 3D is a block diagram illustrating an embodiment of a conductor ontwo layers of a multilayer circuit board. In the example shown,conductor 360 is connected to conductor 362 on one layer of a circuitboard by means of a serpentine similar to the serpentine in FIG. 3A.Conductor 362 on one layer is connected to conductor 366 on a secondlayer (shown by a dashed line) by means of via 364 which connects thetwo layers together. In this way the two serpentine conductors shown inFIG. 3D are wired together in series. While only two layers are shown,this method can be applied to any number layers.

FIG. 3E is a block diagram illustrating an embodiment of a multilayercircuit board with five serpentine conductors on each one of multiplelayers. In the example shown, conductor 380 is connected to conductor382 by means of the serpentines which are wrapped around on each othersimilar to the serpentine in FIG. 3A. As shown, the 5 serpentines arewired in series. The serpentine conductors in each layer can then beconnected to identical serpentines on other layers by means of a viasuch as via 384. Any number of layers could be connected together inthis manner. For example, if six layers are used and each layer isconnected in series with the subsequent layer similar as the layers inFIG. 3D are connected, then there would be thirty serpentine conductorsall connected in series.

In some embodiments, the planar conductors are made out of stamped andlaminated (or laminated then stamped) metal. The metal layers areseparated by an insulated layer and connected to each other with metalvias in the insulated layer. In various embodiments, the conductorscomprise wound wire or placed wire in a form or potted in an epoxy orplastic. In various embodiments, the conductors are in a serpentineshape, are in a coil shape, are on a single layer, are on a plurality oflayers, are on a planar surface, are three dimensional in shape (e.g., aspiral, a laddered serpentine, etc.), or any other appropriateconfiguration for offering an area to a magnetic flux that results in ageneration of power in the event that there is relative motion betweenthe conductor(s) and the multipole magnet.

In some embodiments, the serpentine conductor offers areas appropriatefor a two dimensional array of alternating polarity magnets.

FIG. 4A is a block diagram illustrating an embodiment of a multipolemagnet. In the example shown, the end view of magnet stripes (e.g.,north end stripe 400, south end stripe 402) in a mutlipole magnet areshown along with magnetic field lines (e.g., field lines 404). Directlyabove the center of one of the poles the magnetic field is almostentirely in the Y direction. Directly above the transition from one poleto another, the magnetic field lines are almost entirely in theX-direction.

FIG. 4B is a block diagram illustrating an embodiment of a multipolemagnet in the form of a magnetic sheet. In the example shown, themagnetic sheet is poled such that it has stripes or lines of alternatingpolarity. Magnet stripe 420 is a north section and magnet stripe 422 isa south poled section. The dotted lines 424 indicate boundaries betweenmagnetic stripes, but are not physical separations in the magneticsheet.

In some embodiments, the magnetic sheet is poled such that it has a twodimensional array of magnets of alternating polarity.

FIG. 4C is a block diagram illustrating an embodiment of a multipolemagnet in the form of an array of bar magnets. In the example shown, thebars are arranged in alternating fashion. As shown in the figure, barmagnet 440 is placed with its north pole facing up, and the adjacent barmagnet 442 is placed with its south pole facing up. In some embodiments,bar magnets are affixed to a plane or flat substrate with an adhesive.

FIG. 5A is a block diagram illustrating an embodiment of a powergenerator. In the example shown, directly above the center of one of thepoles (e.g., poles of magnetic stripe 500 or magnetic stripe 502), themagnetic field is almost entirely in the Y direction. It is the Ydirection magnetic field that is enclosed by conductors 506. As theproof mass (e.g., the multipole magnet sheet in this diagram) moves backand forth in the X direction, the magnetic flux enclosed by conductors506 changes generating a voltage across and/or a current in conductors506. Circuit board 504 (e.g., a stationary printed circuit board (PCB))includes conductors 506 (e.g., lines of metal etched to appropriateshapes using standard PCB fabrication). As shown, circuit board 504comprises one layer, however, in various embodiments comprises aplurality of layers.

It should be noted that the Y direction magnetic flux experienced byconductors 506 drops off as the magnets move apart in the Y directionbecause the strength of Y direction magnetic field also drops off.However, this effect is small compared to the voltage generated by the Xdirection motion.

FIG. 5B is a block diagram illustrating an embodiment of a powergenerator. In the example shown, power can also be generated from motionalong the y axis. Directly above the transition from one pole to another(e.g., poles of magnetic stripe 520 and magnetic stripe 522), themagnetic field lines are almost entirely in the X-direction. Motion inthe Y direction will produce voltage across coil conductors 526. Coilconductors 526 are shown in cross section. The flux linked by the coilswill drop off as the magnets (or multilayer circuit board 524 in someembodiments) moves in the Y direction. Coil conductors 526 of FIG. 5Band coil conductors 506 of FIG. 5A can coexist on multilayer circuitboard 524 (e.g., a PCB). Thus power can be generated by motion in boththe X and Y direction.

It should be noted that the embodiment shown in FIG. 5B can alsogenerate power by motion in the X direction. As the multipole magnetmoves in the X direction, the X direction magnetic flux enclosed byconductors 526 changes creating a voltage across those coil conductors.Coil conductors 526 of FIG. 5B and coil conductors 506 of FIG. 5A cancoexist and both produce power from motion in either the X or Ydirections.

FIG. 6 are block diagrams illustrating embodiments of a coil conductor.In some embodiments, coil conductors in FIG. 6 are used to implement 526of FIG. 5B. In the example shown, top view of multilayer circuit board600 includes conductors 602 and conductors for current to be generatedin response to flux changes. Conductors 602 and conductors 622 andconductors 642 show a coil structure used to capture flux changes. Insome embodiments, conductors 602 are connected to a power managementcircuit using lines 604. In various embodiments, conductors 602 areconnected in parallel, in series, or in any other appropriate mannerwith a power management circuit. Top view shows cross section A andcross section B lines. Cross section A shows a side view of multilayercircuit board 620. Cross section B shows a side view orthogonal to crosssection B of multilayer circuit board 640.

FIG. 7 is a block diagram illustrating an embodiment of a powermanagement circuit. In the example shown, power management circuit 700comprises diode rectifier 702, capacitor 704, DC-DC converter 706,battery 708, and electronic load 710. Conductors exposed to changingmagnetic flux produce a voltage/current that is fed into diode rectifier702. Diode rectifier 702 rectifies an alternating voltage/current to asingle polarity voltage/current. The single polarity voltage/current issmoothed using capacitor 704. The smoothed voltage/current is convertedto a desired DC value using DC-DC converter 706. DC-DC converter 706comprises a switch allowing a portion of an input voltage/current tocharge a capacitor. The portion can be varied by varying the amount thatthe switch is on. The portion controls the voltage converted to. Theconverted voltage is fed to battery 708 and electronic load 710. In someembodiments, there is a switch between battery 708 output and electronicload 710 to control whether the output power is allowed to be input toelectronic load 710.

FIG. 8 is a flow diagram illustrating an embodiment of a process forgenerating power. In the example shown, in 800 DC power is provided as aresult of relative motion between an array of magnets and a conductor,wherein the array comprises a one dimensional or two dimensional arrayof magnets, and wherein the conductor comprises a serpentine conductorthat is on a plurality of layers of a multilayer printed circuit board.

FIG. 9 is a flow diagram illustrating an embodiment of a process forgenerating power. In the example shown, in 900 DC power is provided as aresult of relative motion between a sheet magnet and a conductor,wherein the array comprises a one dimensional or two dimensional arrayof alternating magnetic poles, and wherein the conductor comprises aserpentine conductor that is on one or more planes.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, the invention is not limitedto the details provided. There are many alternative ways of implementingthe invention. The disclosed embodiments are illustrative and notrestrictive.

What is claimed is:
 1. A power generator comprising: A first array ofmagnets positioned on a planar surface, wherein the first arraycomprises a one dimensional or two dimensional array of magnets; a firstconductor, wherein the first conductor comprises a first serpentineconductor that is on a plurality of layers of a first multilayer printedcircuit board; a power management circuit, wherein the power managementcircuit provides DC power as a result of relative motion between thefirst array of magnets and the first conductor.